Dimerization or codimerization of alpha-olefins

ABSTRACT

THERE IS DISCLOSED A PROCESS FOR THE DIMERIZATION OR CODIMERIZATION OF A-OLEFINS BY MEANS OF A CATALYST SYSTEM COMPRISING (A) AN ORGANOMETALLIC COMPOUND (B) A NITROGEN CONTAINING LIGAND AND (C) THE REACTION PRODUCT OF A TUNGSTEN HALIDE AND A MONOCARBOXYLIC ACID OR A SEMIESTER OF A DICARBOXYLIC ACID.

United States Patent 3,784,629 DIMERIZATION 0R CODIMERIZATION 0F u-OLEFINS Neil A. Maly, Tallmadge, Henry R. Menapace, Stow, and Gerald S. Benner, Tallmadge, Ohio, assignors to The Goodyear Tire & Rubber Company, Akron, Ohio No Drawing. Filed Mar. 9, 1972, Ser. No. 233,279 Int. Cl. C07c 3/10 US. Cl. 260-68315 D 7 Claims ABSTRACT OF THE DISCLOSURE There is disclosed a process for the dimerization or codimerization of a-olefins by means of a catalyst system comprising (A) an organometallic compound (B) 2. nitrogen containing ligand and (C) the reaction product of a tungsten halide and a monocarboxylic acid or a semiester of a dicarboxylic acid.

This invention is directed to a process for the dimerization or codimerization of a-olefins by means of a catalyst system comprising (A) an organometallic compound, (B) a nitrogen containing ligand and (C) the reaction product of a tungsten halide and a monocarboxylic acid or the half-ester or semi-ester of a dicarboxylic acid.

By the term olefin dimerization is meant that two moles of an olefin are dimerized, for instance, two moles of propylene are dimerized to produce one mole of hexene. By the term codimerization is meant that two dissimilar olefins are dimerized to form a new olefin, for instance, one mole of propylene is codimerized with one mole of 1- butene to form'one mole of a-heptene.

The a-olefins which are dimerized or codimerized in accordance with this invention are olefins containing from 2 through 8 carbon atoms and may be straight or branched chain olefins. Representative of such olefins are ethylene, propylene, 1 'butene, isobutene, l-heptene, Z-methyl- 1- butene, 2-ethyl-l-butene, l-hexene, Z-methyl-l-pentene, 2- methyl-l-hexene, l-pentene, Z-methyl-I-heptene, l-octene and other branched or straight chain u-olefins containing from 2 through 8 carbon atoms.

According to the invention, olefins containing from 2 through 8 carbon atoms are dimerized or codimerized by means of a catalyst comprising,

(A) at least one organometallic compound selected from the group consisting of:

wherein R is an alkyl radical containing from 1 through 10 carbon atoms, X is a halogen from the group of chlorine, bromine and iodine, n is at least 1 but not more than 2 and M is from the group of aluminum, indium, boron and gallium;

(B) at least one ligand of the formula:

wherein R is selected from the group of hydrogen, alkyl, cycloalkyl, alkenyl and aralkyl; R is selected from the group of alkyl, cycloalkyl, alkenyl, aryl, aralkyl and alkaryl; and R is selected from the group of hydrogen, alkyl, cycloalkyl, alkenyl and aralkyl; and wherein R R and R contain from 1 through 20 carbon atoms; and if R is aryl or alkaryl then at least one of R and R must be hydrogen, and;

(C) the reaction product of (1) at least one tungsten salt selected from the group consisting of tungsten hexachloride, tugnsten hexabromide, tungsten pentachloride, tungsten pentabromide, tungsten oxytetrachloride, tungsten oxytetrabromide, and tungsten oxytetraiodide and and (2) at least one acidic compound selected from the group consisting of:

wherein R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl, which contain from 1 through 20 carbon atoms:

wherein n is from 0 through 12 and R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl, which contain from 1 through 20 carbon atoms; and:

wherein R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl, which contain from 1 through 10 carbon atoms.

In the practice of this invention, it is generally desirable to conduct the dimerization or codimerization as a continuous process. However, batch processes may be successfully employed. The temperature at which the dimerization or codimerization reaction of this invention is conducted depends somewhat on the reactants employed and the rate of reaction desired. Generally temperaurtes ranging from about 0 C. to about 150 C. are employed with about 20 C. to about C. being more preferred.

If a continuous process is employed, the rate at which the process is conducted, again, will depend on the temperature employed and the conversion desired. The rate is usually indicated as liquid residence times. In this invention residence times will vary from about 1 minute to 3 hours with 5 minutes to 1 hour being more preferred.

The pressure of the dimerization or codimerization process has not been found to be too critical and may vary broadly from about 0 to about 1000 pounds per square inch gauge (p.s.i.g.) with about 50 to about 500 p.s.i.g. being more preferred.

In the practice of this invention, it is usually desirable to employ pure olefins as the only reactants. However, it may be desirable to employ a diluent for such reasons as a heat transfer medium and the like. If a diluent is employed, it should obviously not react with either the reactant or the resulting products. Representative of such inert diluents may be the paraffin hdyrocarbons such as hexane, pentane, propane, as well as other gases or liquids which are known to be inert. Also suitable are chlorobenzene, benzene and the like.

The first catalyst component is a reducing agent responding to the formulae:

wherein n is a whole number of at least one and not more than two, R is an alkyl radical containing from 1 to 10 carbon atoms; and X is a halogen such as chlorine, bromine or iodine; and M is a metal from the group of boron, aluminum, gallium and indium. Representative of such organometallic compounds are ethylaluminum dichloride, diisobutylaluminum bromide, propylaluminum diiodide, hexylaluminum bromide, diethylaluminum chloride, decylaluminum diiodide, diheptylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum sequibromide and the like. Also representative of the compounds useful in this invention are ethyl boron dichloride, diisobutyl boron bromide, hexyl boron iodide, diethyl boron fluoride, diheptyl boron chloride and the like. Also useful in this invention are the gallium and indium compounds as set forth above, where gallium and indium are substituted for aluminum and boron. 'It is preferred to employ ethylaluminum dichloride, ethylaluminum sesquichloride or diethylaluminum chloride.

The second catalyst components are certain nitrogencontaining ligands responding to the formula:

wherein R is selected from the group of hydrogen, alkyl, cycloalkyl, alkenyl and aralkyl; R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, aryl and alkaryl; R is selected from the group of hydrogen, alkyl, cycloalkyl, alkenyl and aralkyl; and if R is aryl or alkaryl, then at least one of R and R must be hydrogen.

Representative of ligands responding to this formula are dimethylpentenylamine, methylpentenylamine, cyclopentylmethylamine, 2 chlorocyclopentylamine, benzylamine, 4-chlorobenzylamine, phenylbutenylamine, phenylbutylamine, 4-chlorophenylmethylamine, phenylcyclopentylamine, 2-chloroaniline, 4-chloroaniline, 4-methoxyaniline, 4-methylaniline, cyclohexylamine, 2-methylcyclohexylamine, 4-chloro-2-methylaniline, dicyclohexylamine, 4-chlorocyclohexylamine, phenylcyclohexylamine, 4-carbomethoxyaniline, 4-nitroaniline, 4-diethylaminoaniline, tributylamine, triisobutylamine, methylamine, t-butylamine, cyclopentylamine, aniline, Z-methylaniline, 3-butylaniline, 2-nitroaniline, 2,4-dimethylaniline, 3,5-dimethylaniline, 2,6-dimethylaniline, 2,6-dimethyl-4-bromoaniline. Also amines wherein the nitrogen atom constitutes a part of a heterocyclic saturated ring may be used; such a compound is represented by 4-methyl piperidine and other substituted piperidines; also tetrahydropyrroles and substituted tetrahydropyrroles, also piperazines and substituted piperazines. It is preferred to use aniline, Z-methyl or 4-methyl aniline, 2-nitro or 4-nitro aniline, 3-butylaniline, cyclohexylamine, dibutylamine, 2,4-dimethylaniline or 2,6-dimethylaniline.

The third component of the catalyst system of this invention is the reaction product of tungsten hexachloride, tungsten hexabromide, tungsten pentachloride, tungsten pentabromide, tungsten oxytetrachloride, tungsten oxytetrabromide and tungsten oxytetraiodide, with certain acidic compounds comprising a monocarboxylic acid or the half-esters or semi-esters of a dicarboxylic acid.

The dicarboxylic acids to react with the tungsten halides may be defined by the formula:

wherein R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl which contain from 1 through 20 carbon atoms. Representative of such monocarboxylic acids are 3-ethylhexanoic acid, cyclohexanecarboxylic acid, butenoic acid, phenol acetic acid, p-toluic acid, acetic acid, Z-ethylhexanoic acid, 2,2-diethylhexanoic acid and benzoic acid, with 2-ethylhexanoic acid being preferred.

The class of semi-esters or half-esters of dicarboxylic acids can be both aliphatic or aromatic in nature. The aliphatic compounds may be represented by the formula:

wherein It may range from through 12 and R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl which contain from 1 through carbon atoms. Representative of such compounds are monomethyl malonate, monomethyl oxalate and monoethyl adipate and other half-esters of dicarboxylic acids which 0 LOB wherein R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl, which contain from 1 through 10 carbon atoms. Representative of such materials are monomethyl phthalate, monobutyl phthalate, monodecyl phthalate, monophenyl phthalate, monomethyl phthalate, monooctyl phthalate and other semiesters using the substituents as defined above, with monomethyl phthalate being preferred.

To prepare the reaction product of the tungsten halides and the monocarboxylic acids or the semi-esters of a dicarboxylic acid is straight forward and requires no special technique. The usual practice is to react one mole of the desired tungsten halide with either one or two moles of the desired acidic compound while they both are dissolved in an inert solvent such as chlorobenzene, pentane and the like. The tungsten halide is usually dissolved in, the solvent at about 0.1 molarity and the proper amount of the acidic compound added. Then the reaction product is usually analyzed to determine the exact amount of tungsten in the mixture to determine how much to use.

The amount of catalyst used in the process is not critical so long as a catalytic amount is employed. As little an amount of catalyst as 0.01 parts by weight of the tungsten (with the other components in the proper ratios) has shown fair catalytic activity. The amount employed will, of course, depend on factors such as the rate desired, the pressure and temperature employed and the like. Persons skilled in the art will be able to determined the proper amount without undue problems.

The molar relationship between the catalyst components employed in this invention may vary quite widely. For instance, the molar relationship of the organometallic compound (M) to the molar relationship of the nitrogencontaining ligand (N) to the reaction product of the tungsten halide and the carboxylic acid or semi-ester of the dicarboxylic acid (W) may vary in the relationship M/N/W of from 4 to 40/1 to 3/1. A more preferred ratio of the catalyst components would be N/N/W of from 10-20/1.5-2.5/1.

There is no particular technique required to prepare the catalyst of this invention. The catalyst may be prepared in situ or they may be pre-formed. By the term in situ is meant that each individual catalyst component is added to the reaction mixture. By the term pre-formed is meant that the catalyst components are pre-mixed and then added to the polymerization mixture. It is usually the practice to add the catalyst components while they are dissolved in one of the inert solvents mentioned herein. This is not an absolute requirement but for better control of accuracy, this technique has been employed.

The practice of this invention may be further illustrated by reference to the following examples which are intended to be representative rather than restrictive of the scope of the invention.

In these examples 0.02 moles of propylene were reacted, using as a catalyst 0.002 moles of ethylaluminum sesquichloride, 0.0004 moles of aniline and 0.0002 moles of the reaction product of one mole of tungsten hexachloride with the various acidic compounds listed in the table below in the molar relationships listed in the table. The tungsten hexachloride prior to being mixed with the acidic compound had a molarity of 0.1, the ethylaluminum sesquichloride had a molarity of 2 and the aniline had a molarity of 0.2, all in chlorobenzene.

TABLE I Percent 2,3- 2- 4-methyldimethylmethyl-1- Ex. Acidic compound Conv. Sel. pentenes l-butene pentene 1 2 moles 2-ethyl hexanoic acid-. 62 93 7. 1 52 34 2 2moles benzoic acid 66 79 6.3 46 28 3 1 mole monoethyl malonate--- 100 5. 1 61 43. 5 4 1 mole benzoic acid 77 90 7. 1 52 30 While certain representative embodiments and details 0 have been shown for the purpose of illustrating the ma 0K vention, it will be apparent to those skilled in this art that T various changes and modifications may be made therein C-QR: without departing from the spirit or scope of the rnvention.

What is cla med is: wherein R is selected from the group of alkyl, cyclo- A process 111 whlch -p contamlpg r 2 alkyl, alkenyl, aralkyl, alkaryl and aryl, which conthrough 8 carbon atoms are dimerized or codimerlzed by wil f 1 through 10 c b atom means of a catalyst comprising, in which the mole relationship between catalyst compo- (A) at least one organometallic compound selected from the group consisting of:

a z s wherein R is an alkyl radical containing from 1 through 10 carbon atoms, X is a halogen from the group of chlorine, bromine and iodine, n is at least 1 but not more than 2 and M is from the group of aluminum, indium, boron and gallium;

(B) at least one ligand of the formula:

wherein R is selected from the group of hydrogen, alkyl, cycloalkyl, alkenyl and aralkyl; R is selected from the group of alkyl, cycloalkyl, alkenyl, aryl, aralkyl and alkaryl; and R is selected from the group of hydrogen, alkyl, cycloalkyl, alkenyl and aralkyl; and wherein R R and R contain from 1 through 20 carbon atoms; and if R is aryl or alkaryl, then at least one of R and R must be hydrogen, and;

(C) the reaction product of (1) at least one tungsten salt selected from the group consisting of tungsten hexachloride, tungsten hexabromide, tungsten pentachloride, tungsten pentabromide, tungsten oxytetrachloride, tungsten oxytetrabromide and tungsten oxytetraiodide and (2) at least one acidic compound selected from the group consisting of:

and

wherein R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl, which con tain from 1 through 20 carbon atoms:

wherein n is from 0 through 12 and R is selected from the group of alkyl, cycloalkyl, alkenyl, aralkyl, alkaryl and aryl, which contain from 1 through 20 carbon atoms, and:

nents (A)/ (C) ranges from about 10/ 1 to about 20/1 and the mole relationship between catalyst components B/C ranges from about 1.5/1 to about 2.5/1, to form dimers of said a-olefins, and in which 1 mole of the tungsten salt is reacted with 1 or 2 moles of the acidic compound.

2. The process according to claim 1 in which the 0:- olefin is propylene.

3. The process according to claim 1 in which the organometallic compound is selected from the group of ethylaluminum dichloride, diethylaluminum chloride and ethylaluminum sesquichloride.

4. The process according to claim 1 in which the ligand of the formula:

NR1R2R3 is aniline and the acidic compound is monoethyl malonate.

7. The process according to claim 1 in which the aolefin is propylene, the organometallic compound is ethylaluminum sesquichloride, the ligaml of the formula:

is aniline and the acidic compound is 2-ethylhexanoic acid.

References Cited UNITED STATES PATENTS 3,544,649 12/1970 Dixon et al 260-683 3,318,860 5/1967 Eichenbaum 25Z429 3,558,518 1/ 1971 Zuech 25Z429 PAUL M. COUGHLAN, JR., Primary Examiner 25Z429 B, 431 N US. Cl. X.R.

- STATES "PATENT OFFICE I CERTIFICATE O CORRECTION Pltent No. 378M629 mug l- -7 'Invlntofll) Neil A'Maly, Henry R Menepace and Gerald S Benner It is certified that error appears in the above-identified patent v and that aid Letters Patent: an hereby corrcctcd 0 shown below r- Col line 33 "temperaurces" should read as v temperatures Col 3, line 5 R g or;

should' -"read BME'CH' *Si'neda d sealed thie 16th day OffJiuly 1974.

CSE Ll Attestg I I MCCOY M. GIBSON, JR. c. MARSHALL DANN Attes't-i ng' Officer Commissioner of Patents 

